Why "Go SMS Pro" is making my mobile more slow?????

[AC Question]

I am using Go SMS Pro for almost 2 years it was working fine til feb 2017, after that it started making my mobile more slow... When i delete this app my mobile become fast as runs.. (I am using Samsung Note 3 with 3GB Ram) i did reset my mobile with this thought that perhaps there a bug might got in my mobile but after re-installing Go SMS Pro my mobile becomes too much slow... I need expert suggestion.... Kindly reply your opinion... I shall be thankful to you.

Regards,
Dr. Rohail